1. Field of the Invention:
The present invention is directed to a device for regulating the pressure drop of at least one of the flows in a multiflow turbojet engine. The device includes a stage composed of variable-adjustment vanes located in the secondary annular channel surrounding the primary channel, a vane control ring, connection means between the control ring and the vanes and rotation control means of the control ring.
2. Description of the Prior Art
The regulating of the pressure drop of the secondary air flow in a multiflow turbojet is necessary in order to obtain the best possible flight conditions in order to adjust, in a constant manner, the relationship of the outputs of the primary and the secondary flows in the flight conditions encountered. This adjustment of the bypass dilution ratio favors the creation of a homogeneous mixture of the two flows and allows a satisfactory afterburner operation both under conditions of subsonic flight and of supersonic flight.
For example, French Patent No. 995,131 discloses a device which can act on the secondary flow by means of obturator flaps located in the secondary channel and permits the dilution ratio to be reduced without any appreciable change of the rotating speeds of the mechanical components.
French Patent No. 2,445,438 describes a mechanism for actuating obturation vanes in which the vanes are located in the secondary channel and pivot about axes which turn in bearings carried by the inner and outer walls of the secondary channel. The axis crossing the outer wall is fixed to one end of a lever, the other end of which turns in a fork integral with a ring. A jack causes the ring to rotate, thus causing the vanes to rotate and vary the degree of obturation of the channel. The modification of the pressure drop of the channel according to this mechanism is intended to assist in starting with the motor air, to reduce the level of thrust when reducing speed on the ground and to reduce the secondary flow under idling conditions.